U.S. patent application number 11/573743 was filed with the patent office on 2008-12-25 for stator and motor, to which the stator is applied, and method of manufacturing the stator.
This patent application is currently assigned to MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.. Invention is credited to Yoshihiro Kira, Yasuaki Matsushita, Masayuki Morioka, Shinya Tamura.
Application Number | 20080315710 11/573743 |
Document ID | / |
Family ID | 37942486 |
Filed Date | 2008-12-25 |
United States Patent
Application |
20080315710 |
Kind Code |
A1 |
Morioka; Masayuki ; et
al. |
December 25, 2008 |
Stator and Motor, to Which the Stator is Applied, and Method of
Manufacturing the Stator
Abstract
There is provided a stator in which a plurality of divided
stators are annularly combined with each other, and each divided
stator includes: a divided lamination iron core having teeth
portion and a yoke portion, and constructed by laminating
electromagnetic steel sheets divided by the teeth unit; insulating
bodies provided at the divided lamination iron core; and
concentrated winding wound around the divided lamination iron core
through the insulating body. In this case, the divided lamination
iron core is held by the insulating bodies and the concentrated
winding.
Inventors: |
Morioka; Masayuki; (Osaka,
JP) ; Matsushita; Yasuaki; (Kyoto, JP) ; Kira;
Yoshihiro; (Osaka, JP) ; Tamura; Shinya;
(Osaka, JP) |
Correspondence
Address: |
RATNERPRESTIA
P.O. BOX 980
VALLEY FORGE
PA
19482
US
|
Assignee: |
MATSUSHITA ELECTRIC INDUSTRIAL CO.,
LTD.
Osaka
JP
|
Family ID: |
37942486 |
Appl. No.: |
11/573743 |
Filed: |
July 11, 2006 |
PCT Filed: |
July 11, 2006 |
PCT NO: |
PCT/JP2006/313728 |
371 Date: |
February 15, 2007 |
Current U.S.
Class: |
310/216.044 ;
29/596 |
Current CPC
Class: |
H02K 3/325 20130101;
Y10T 29/49078 20150115; Y10T 29/49009 20150115; H02K 3/522
20130101 |
Class at
Publication: |
310/217 ;
29/596 |
International
Class: |
H02K 1/12 20060101
H02K001/12; H02K 15/02 20060101 H02K015/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 12, 2005 |
JP |
2005-297501 |
Claims
1. A stator, in which a plurality of divided stators are annularly
combined with each other, comprising: a divided stator of the
divided stators including: a divided lamination iron core having a
teeth portion and a yoke portion, and constructed by laminating
electromagnetic steel sheets divided by the teeth unit; an
insulating body provided at the divided lamination iron core; and a
concentrated winding wound around the divided lamination iron core
through the insulating body, wherein the divided lamination iron
core is held by the insulating body and the concentrated
winding.
2. The stator of claim 1, wherein the insulating body is provided
at both sides in a laminating direction of the divided lamination
iron core and at both sides of the yoke portion in such a manner
that the divided lamination iron core is covered by the insulating
body.
3. The stator of claim 1, wherein the divided lamination iron core
has a recess portion at an outer periphery of the yoke portion, and
an opening portion of the recess portion is smaller than an
inside.
4. A motor comprising: a rotor having a permanent magnet; and a
stator facing the permanent magnet through a certain gap, the
stator, in which a plurality of divided stators are annularly
combined with each other, including: a divided stator of the
divided stators including: a divided lamination iron core having a
teeth portion and a yoke portion and constructed by laminating
electromagnetic steel sheets divided by the teeth unit; an
insulating body provided at the divided lamination iron core; and a
concentrated winding wound around the divided lamination iron core
through the insulating body, wherein the divided lamination iron
core is held by the insulating body and the concentrated
winding.
5. The motor of claim 4, wherein the insulating body is provided at
both sides in a laminating direction of the divided lamination iron
core and at both sides of the yoke portion in such a manner that
the divided lamination iron core is covered by the insulating
body.
6. The motor of claim 4, wherein the divided lamination iron core
has a recess portion at an outer periphery of the yoke portion, and
an opening portion of the recess portion is smaller than an
inside.
7. A method of manufacturing a stator in which a plurality of
divided stators are combined with each other, a divided stator of
the divided stators including: a divided lamination iron core
having a teeth portion and a yoke portion and constructed by
laminating electromagnetic steel sheets divided by the teeth unit;
an insulating body provided at the divided lamination iron core;
and a concentrated winding wound around the divided lamination iron
core through the insulating body, the method of manufacturing the
stator comprising: a step of punching an electromagnetic steel
sheet continuously with an upper press die and lower press die so
as to obtain a divided iron core sheet; a step of discharging the
divided iron core sheet continuously guided by a rail; a step of
taking a certain number of the divided iron core sheets out through
a rod-shaped jig; a step of attaching the insulating body in such a
manner that the certain number of divided iron core sheets is
covered by the insulating body; a step of holding the divided iron
core sheets with an iron core holding jig and conducting a
concentrated winding around the divided iron core sheets; a step of
removing the iron core holding jig to obtain the divided stator;
and a step of connecting annularly the divided stators with each
other.
8. The method of manufacturing a stator of claim 7, wherein the
divided iron core sheet has a recess portion, the opening portion
of which is smaller than an inside, on an outer periphery of the
yoke portion, and a cross-section of the rod-shaped jig is larger
than the opening portion of the recess portion.
Description
TECHNICAL FIELD
[0001] The present invention relates to a stator in which a loss
caused by lamination of electromagnetic steel sheets is reduced.
The present invention also relates to a structure of a motor to
which the stator is applied and a method of manufacturing the
stator.
BACKGROUND ART
[0002] Concerning motors mainly used for industrial devices, it is
desired to provide small and highly efficient motors so as to
reduce electric power consumption. In order to accomplish the above
object, highly efficient small motors are mainly used in which an
iron core of a stator is divided by the teeth unit and concentrated
winding is wound around the divided iron core so that a space
factor of a slot winding can be enhanced and a space necessary for
a winding end portion can be reduced.
[0003] Concerning the engineering method in which a certain number
of the divided iron core sheets, which are made by punching an
electromagnetic steel sheet, are laminated and fixed on each other
so as to obtain this divided stator iron core, the following
engineering methods are well known. They are as follows: an
engineering method (a first engineering method) in which the
divided iron core sheets are laminated on each other and the inner
and outer circumferential faces are subjected to laser welding in a
laminating direction; an engineering method (a second engineering
method) referred to as a dowel caulking method or a PAC (Press Auto
Clamp) system, in which a protruding portion and a recessing
portion, which are made by conducting half blanking on the divided
iron core sheet in the laminating direction, are engaged with each
other and an upper core and a lower core are connected with each
other by means of caulking; and an engineering method (a third
engineering method) in which electromagnetic steel sheets for
adhesion iron cores are used as the divided iron core sheets and
laminated and fixed to each other by pressuring and heating
(thermal-pressure bonding). This third engineering method is
disclosed in the Japanese Patent Unexamined Publication No.
H11-162722.
[0004] In the first engineering method, the following problem may
be encountered. An eddy current loss is caused on a surface facing
a permanent magnet of a rotor. Therefore, a motor efficiency is
deteriorated. In order to reduce this eddy current loss, a method
is proposed in which the divided iron core sheets are laminated and
then integrated with each other into one body by means of resin.
This method is disclosed in Japanese Patent Unexamined Publication
No. 2000-333388. Even in the second engineering method, an eddy
current loss is caused at an engagement portion in which a
protruding portion and a recessing portion made by half blanking
are engaged with each other.
[0005] According to the third engineering method, it is possible to
reduce the aforementioned eddy current loss. However, commonly used
electromagnetic steel sheets, which are used for the other
engineering methods, are coated with inorganic coating material. On
the other hand, in the case of the above engineering method, in
order to ensure the adhesion strength, film thickness of coating
used for adhesion of the electromagnetic steel sheets for the iron
core is increased. Therefore, a quantity of iron per unit
lamination length is lowered, that is, a space factor of the iron
core is lowered. In general, a cost of this electromagnetic steel
sheet used for adhesion iron core is higher than a cost of the
electromagnetic steel sheet on which inorganic coating material is
coated. Accordingly, the cost of the divided fixing iron core is
raised.
[0006] In the conventional stator and the engineering method of
manufacturing the stator, the following problems may be encountered
when the divided iron core sheets are laminated and fixed. That is,
an eddy current loss of the laminated iron core obtained by the
laser welding or the dowel caulking system is large. A space factor
of the laminated iron core obtained by the adhesion lamination
engineering method is low and the manufacturing cost is high.
[0007] When the divided iron sheets are taken out without
laminating and fixing them in a metallic die right after the
divided iron sheets have been punched out with a punching die, the
iron cores are discharged from the metallic die being separated
from each other. Therefore, it becomes necessary to arrange the
iron cores so that directions and both sides of the iron cores can
be made to be proper. Accordingly, it takes much labor to arrange
the iron cores for lamination.
DISCLOSURE OF THE INVENTION
[0008] The constitution of the stator of the present invention is
described as follows. The present invention provides a stator in
which a plurality of divided stators are annularly combined with
each other, each divided stator including: a divided lamination
iron core having a teeth portion and a yoke portion, and
constructed by laminating electromagnetic steel sheets divided by
the teeth unit; an insulating body provided at the divided
lamination iron core; and a concentrated winding wound around the
divided lamination iron core through the insulating body. In this
case, the divided lamination iron core is held by the insulating
body and the concentrated winding.
[0009] The present invention further includes a motor to which this
stator is applied. The present invention further includes a method
of manufacturing the stator which includes the following steps.
[0010] The method of manufacturing the stator includes: a step of
punching an electromagnetic steel sheet with an upper press die and
lower press die so as to obtain a divided iron core sheet; a step
of discharging the divided iron core sheet continuously guided by a
rail; a step of taking a certain number of the divided iron core
sheets out through a rod-shaped jig; a step of attaching the
insulating body in such a manner that the certain number of divided
iron core sheets is covered by the insulating body; a step of
holding the divided iron core sheets with an iron core holding jig
and conducting a concentrated winding around the divided iron core
sheets; a step of removing the iron core holding jig to obtain the
divided stator; and a step of connecting annularly the divided
stators with each other.
[0011] By this constitution and the manufacturing method, it is
possible to provide a stator and a highly efficient small motor of
low price, to which this stator is applied, without increasing an
eddy current loss and without lowering a space factor of the iron
core.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a sectional view of a motor of Embodiment 1 of the
present invention.
[0013] FIG. 2 is a schematic illustration of an essential part of a
stator of the motor shown in FIG. 1.
[0014] FIG. 3 is a schematic illustration of an essential part of a
stator of Embodiment 2 of the present invention.
[0015] FIG. 4 is a schematic illustration showing a method of
manufacturing a divided lamination iron core of a stator shown in
FIG. 3.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0016] 1 Rotor
[0017] 3 Iron core of rotor
[0018] 4 Permanent magnet
[0019] 11, 21 Stator
[0020] 12, 22 Divided stator
[0021] 13a, 13b, 14a, 14b Insulating body
[0022] 15, 25 Concentrated winding
[0023] 16, 26 Divided lamination iron core
[0024] 16a, 26a Teeth portion
[0025] 16b, 26b Yoke portion
[0026] 23a, 23b, 24a, 24b Insulating body
[0027] 26e Recess portion of divided lamination iron core
[0028] 32 Electromagnetic steel sheet
[0029] 33 Upper press die
[0030] 34 Lower press die
[0031] 35 Rail
[0032] 36 Rod-shaped jig
[0033] 46 Divided iron core sheet
[0034] 46e Recess portion of divided iron core sheet
PREFERRED EMBODIMENTS FOR CARRYING OUT THE INVENTION
[0035] Exemplary embodiments of the present invention are
demonstrated hereinafter with reference to the drawings.
Embodiment 1
[0036] FIG. 1 is a sectional view of a motor of Embodiment 1 of the
present invention. As the motor of the present embodiment, an inner
rotor type 8-pole-12-slot type motor is exemplarily shown here. In
FIG. 1, stator 11 is composed in such a manner that twelve divided
stators 12 are annularly connected to each other. Concerning
joining faces of yoke portion 16b of each divided stator 12, recess
portion 16d is provided at one of the joining faces and protruding
portion 16e is provided at the other face of the joining faces. Due
to this constitution, it is possible to conduct positioning and to
ensure a mechanical strength.
[0037] Around teeth portion 16a of each divided stator 12,
concentrated winding 15 is wound through insulating bodies 13a, 13b
before conducting a connection.
[0038] On the other hand, 8 poles of permanent magnets 4, that is,
4 pairs of permanent magnets 4 are fixed onto an outer periphery of
rotor iron core 3 of rotor 1. In this case, one pair of permanent
magnets includes one N-pole and one-S pole. Rotary shaft 2 is fixed
to a center of rotor iron core 3 by means of press-fitting. Rotary
shaft 2 is pivotally supported by a bearing (not shown). An outer
periphery of permanent magnet 4 is reinforced by a resin tape or a
metallic sheet (not shown) made of non-magnetic material. Permanent
magnet 4 of rotor 1 and a forward end portion of teeth portion 16a
of stator 11 face each other through a certain gap.
[0039] FIG. 2 is a schematic illustration of an essential part of
stator 11 of the motor shown in FIG. 1. Divided stator 12 is
composed as follows. A certain number of divided iron core sheets,
which are made by punching an electromagnetic steel sheet into a
certain shape, are laminated on each other, so that divided
lamination iron core 16 can be obtained. This divided lamination
iron core 16 is held by an iron core holding jig as described
later, however, the divided iron core sheets are not fixed to each
other. Onto both sides of teeth portion 16a of this divided
lamination iron core 16, insulating bodies 13a, 13b are
respectively press-fitted. Onto both end faces in a laminating
direction of teeth portion 16a of this divided lamination iron core
16, insulating bodies 14a, 14b are respectively press-fitted. These
insulating bodies 13a, 13b, 14a, 14b are arranged so that divided
lamination iron core 16 is covered by them. In this state, a
certain concentrated winding work is conducted by a winding machine
(not shown). In this way, divided stator 12 is manufactured.
[0040] An end of this winding is connected to a junction terminal
(not shown) provided at insulating body 14a or 14b. After divided
stators 12 are annularly connected to each other, a certain
connection is made.
[0041] Although portions between the divided iron core sheets are
not fixed, the divided iron core sheets are held by concentrated
winding 15 through insulating bodies 13a, 13b, 14a, 14b which are
arranged in such a manner that they cover concentrated winding 15.
Therefore, the divided iron core sheets are not separated from each
other. Unlike the conventional method, it is unnecessary to conduct
laser welding on the divided iron core sheets and to provide an
engagement portion formed out of a recess portion and a protruding
portion by conducting half blanking. Accordingly, an eddy current
loss is not increased. Since it is unnecessary to use an
electromagnetic steel sheet for an adhesion iron core, a space
factor of the iron core is not lowered. Therefore, by using the
stator of this Embodiment 1, it is possible to provide a highly
efficient small motor of low price.
Embodiment 2
[0042] FIG. 3 is a schematic illustration for showing an essential
part of stator 21 of Embodiment 2 of the present invention. Divided
lamination iron core 26 of this embodiment includes recess portion
26e on an outer periphery of the yoke portion. By this recess
portion 26e, divided iron core sheets, which have been obtained by
punching out an electromagnetic sheet with a metallic press die,
are continuously discharged. Therefore, it becomes easy to take out
a certain number of divided iron core sheets and to conduct a
winding work. Except for that, the essential constitution is the
same as that of Embodiment 1.
[0043] A certain number of divided iron core sheets, which are made
by punching an electromagnetic steel sheet into a certain shape,
are laminated on each other, so that divided lamination iron core
26 can be obtained. This divided lamination iron core 26 is held by
an iron core holding jig as described later, however, portions
between the divided iron core sheets are not fixed. Onto both sides
of teeth portion 26a of this divided lamination iron core 26,
insulating bodies 23a, 23b are respectively press-fitted. Onto both
end faces in a laminating direction of teeth portion 26a of this
divided lamination iron core 26, insulating bodies 24a, 24b are
respectively press-fitted. These insulating bodies 23a, 23b, 24a,
24b are arranged in such a manner that divided lamination iron core
26 is covered by them. In this state, a certain concentrated
winding work is conducted by a winding machine (not shown). In this
way, divided stator 22 is manufactured.
[0044] In this connection, an end of this winding is connected to a
junction terminal (not shown) provided at insulating body 24a or
24b. After divided stators 22 have been annularly connected to each
other, a certain connection is made.
[0045] Although the divided iron core sheets are not fixed to each
other, the divided iron core sheets are held by concentrated
winding 15 through insulating bodies 23a, 23b, 24a, 24b which are
arranged in such a manner that they cover concentrated winding 25.
Therefore, the divided iron core sheets are not separated from each
other. Unlike the conventional case, it is unnecessary to conduct
laser welding on the divided iron core sheets and to provide an
engagement portion formed out of a recess portion and a protruding
portion by conducting half blanking. Accordingly, an eddy current
loss is not increased. Since it is unnecessary to use an
electromagnetic steel sheet for an adhesion iron core, a space
factor of the iron core is not lowered. Therefore, by using the
stator of this Embodiment 2, it is possible to provide a highly
efficient small motor of low price.
[0046] FIG. 4 is a schematic illustration showing a method of
manufacturing a divided lamination iron core of a stator in
Embodiment 2 of the present invention. Electromagnetic sheet 32 is
fed onto lower press die 34. By a vertical movement of upper press
die 33, divided iron core sheet 46 is continuously punched out into
a certain shape. Thus punched divided iron core sheet 46 is
continuously and successively discharged in such a manner that
recess portion 46e of divided iron core sheet 46 is being guided by
rail 35 arranged from punching portion 34a of lower press die 34 to
the outside of the device.
[0047] In this connection, recess portion 46e provided at divided
iron core sheet 46 is formed into a substantial circle having an
opening portion, wherein an opening portion of the circle is
smaller than a diameter of the circle.
[0048] In this case, rod-shaped jig 36 is made to come into contact
with an end portion of rail 35 and a certain number of divided iron
core sheets 46 are taken out through recess portions 46e so as to
compose divided lamination iron core 26. When a cross-sectional
shape of this rod-shaped jig 36 is set to be larger than the
opening portion of recess portion 46e, divided iron core sheets 46
do not fall off from rod-shaped jig 36 under the condition that
divided iron core sheets 46 engaged with rod-shaped jig 36 are
taken out from rail 35.
[0049] Next, while insulating bodies 23a, 23b are being attached so
as to be laid on an inner wall of teeth portion 26a of divided
lamination iron core 26 in order to insulate concentrated winding
25 from divided lamination iron core 26, insulating bodies 24a, 24b
are press-fitted from both end portions of divided lamination iron
core 26 in such a manner that insulating bodies 23a, 23b are
interposed between them. Even in this step, divided iron core
sheets 46 do not fall off because of rod-shaped jig 36. Therefore,
divided iron core sheets 46 can be easily aligned on the basis of
rod-shaped jig 36.
[0050] In the next winding step, in divided lamination iron core
26, faces, on which insulating bodies 23a, 23b, 24a, 24b are not
arranged, are held by an iron core holding jig (not shown) and
concentrated winding 25 is conducted in teeth portion 26a of
divided lamination iron core 26 on which insulation treatment has
already been conducted. After that, by removing this jig, divided
stator 22 having concentrated winding 25 can be obtained.
[0051] Then, twelve divided stators 22 are annularly arranged and
divided faces are joined and fixed to each other. After that, ends
of concentrated winding 25 are subjected to a certain connection
processing. In this way, stator 21 is completed. Concerning the
method of fixing the joining portion, for example, laser beam
welding or adhesion, which is a conventional engineering method,
may be adopted. Laser welding, which is conducted on an outer
peripheral portion of the iron core, seldom affects a magnetic flux
and further it is possible to minimize an eddy current loss.
[0052] In this connection, in order to minimize a magnetic loss, it
is preferable that recess portion 46e is provided in an outer
peripheral portion at a center of the magnetic pole and a size of
recess portion 46e is minimized as long as a rod-shaped jig can be
inserted into recess portion 46e. An annular structure such as a
frame may be attached onto an outer periphery of the stator of the
present invention by means of press-fitting or shrinkage fitting.
Further, in order to prevent this annular structure and the stator
from being moved from by a reaction force, a pin may be driven into
recess portion 46e from the outside.
INDUSTRIAL APPLICABILITY
[0053] As described above, according to the present invention, it
is possible to provide a stator and a highly efficient small motor
of low price, to which this stator is applied, without increasing
an eddy current loss and without lowering a space factor of the
iron core. Especially, the motor of the present invention can be
effectively applied as a small motor for industrial use.
* * * * *